Don't go for Monster. It tastes bad and delivers too little energy on too much caffeine. Around 250 mg of it. And I fell asleep drinking a can. To me it tastes like liquid fermented bubble gum with banana flavor. If you want real energy that is worth the price, go with Red Bull. They are even coming out with 3 new flavors some time soon. If you cannot afford Red Bull, Rockstar does the trick, especially the Punched flavor. If you want a real energy buzz, try Nos. It does not taste the best, but it is drinkable and delivers hours of AMAZING energy. Amp is decent too.
The bottom line is, do NOT drink Monster. Unless poor quality is your kind of thing.
One more thing, if you know how, you can get the energy drink-style doses for free, FROM I-DOSER, and they really work.